Why your nose gets sniffly when you cry
It all starts with your lacrimal glands, located on the outer portion of the upper eyes. These peanut-shell-shaped glands create and secrete tears. Most tears will flow over the surface of your eyes and drain out the corners of your eyelids, through the tear ducts, which lead into the nasal cavity. If you cry an abundance of tears, the tears overflow the nasal cavity and start running out of your nose.

Tears help you see better.
Even when you are not crying, tears flow from your lacrimal glands with every blink, moistening your eyes. This moisture - made of water, oil, and mucus - helps to maintain healthy vision. Tears clear your eyes of debris and allow light to enter your eyes so you can see.

Tears flow for 3 reasons.
Think about the times your eyes water, like when you feel overwhelmed by emotion, when you sneeze or have allergies, or when you're peeling onions. Tear experts generally separate the droplets into three types. Basal tears are the kind of tears that clean and lubricate your eyes, supporting your vision. Reflex tears are the ones that stream out when your eyes are irritated by something - the compounds in onions, pollen, bacteria. And emotional tears, well, you know what those are for.

Emotional tears may be an evolutionary adaptation.
We humans may have evolved tears that do more than mere eye-moistening as a means of survival. Evolutionary biologist Oren Hasson suggested that we may have used tears to protect us from predators by making it harder to tell where we were gazing. Or, Hasson wondered, could it be that we evolved emotional tears as a way to show others that we were vulnerable, that we would prefer to make peace? When most people see a crying face, they feel an urge to ask what is wrong, to offer help or empathy. It could be that emotional tears signalled our willingness to trust and become bonded into supportive, protective communities. And crying when we felt fearful or vulnerable or when we felt a sense of unity could then have developed into the kind of emotional crying we all do now and then.

A "good" cry can make you feel better.
Crying is often called "cathartic," a release of pent-up emotions and tensions. But how we really feel after crying may depend on the circumstances and context of your crying – the "when," "where," and "with whom" you cry. In an international study including over 5,000 men and women, certain "good" and "bad" cry patterns emerged. Criers who got support from those around them were more likely to feel better post-sob. Criers got a boost from bawling if they came to a realization, new understanding, or resolution regarding the thing that made them cry.

A "bad" cry may make you feel worse.
Participants in the study mentioned above who suppressed their crying or felt shame as they cried reported that they did not feel as good afterward. A different, smaller study found that crying can be the opposite of cathartic for those with certain depressive symptoms. Those with an inability to experience pleasure did not take pleasure from crying - in fact, they felt worse after they cried than they felt before. The same results applied to those who were out of touch with or unable to express their emotions.

Some people are more prone to cry than others.
The smaller study mentioned above uncovered another pattern about crying. If you are quite empathetic to the suffering of others, you may cry more frequently than the harder-hearted. People who are anxious or neurotic cry both more frequently and more easily than others. And extraverts tend to cry more often during negative situations and are less likely to cry "happy tears."

Babies cry 1 to 3 hours each day.
New parents would probably estimate a much higher tear tally than that! Infants cry to communicate. Their wails and screeches can alert a parent to so many potential issues - hunger, thirst, tiredness, discomfort, boredom, loneliness. Infants cry out for help if they are too cold or too hot, if they have gas, if their diaper is wet, or if they are in the painful throes of teething. Parents may develop an instinctual ability to translate their infant's various cries. And new mothers discover the amazing power of a baby's cry to engorge her breasts with milk. A baby who cries for more than 3 hours a day, more than 3 days a week, for more than 3 weeks may have colic, which is excessive crying without a known cause.

Tear ducts can become blocked.
The ducts that drain tears from your eyes can become blocked due to aging, infection, inflammation, injury, tumour, or cyst. A blocked tear means tears can't be drain properly, causing symptoms of excessive tearing and watery eyes. Blocked ducts can also increase risk of eye infection and inflammation.

Crying can become involuntary.
Yes, any of us can be suddenly overwhelmed by the waterworks. But in certain neurological conditions, crying - along with laughing - can happen uncontrollably. Called pathological laughing and crying (PLC), laughter or sobbing can occur at inappropriate times. PLC can appear as a symptom of stroke, Alzheimer's disease, multiple sclerosis, and amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease).

Amy Toffelmire